Midfielder Julian Green, who made his national team debut last month, and forwards Terrence Boyd and Chris Wondolowski also are among the players who will try to earn spots during the Americans’ pre-World Cup training camp, which opens Wednesday at Stanford, California.

Johnson scored the key first goal against Mexico last September that clinched the Americans’ seventh straight World Cup berth.

“It was a very difficult decision based on what he’s done with me the whole time,” Klinsmann said.

Klinsmann said he viewed Landon Donovan, a veteran of three World Cups, as a pure forward in this squad. Johnson, a member of the 2006 World Cup team, was a victim of numbers as Klinsmann took only six forwards.

Ten players were on the 2010 squad, including left back DaMarcus Beasley, like Donovan a veteran of three World Cups.

Five players did not appear in any of the 16 qualifiers for the 2014 World Cup: No. 3 goalkeeper Nick Rimado along with Brooks, Green, Wondolowski and Yedlin.

Half the players are from Major League Soccer, with four each from England’s Premier League and Germany’s Bundesliga. Two are from Mexico’s league, and one each from Austria, France, Netherlands, Norway and Turkey.

The Americans play friendlies against Azerbaijan on May 27 at San Francisco; Turkey on June 1 at Harrison, New Jersey; and Nigeria on June 7 at Jacksonville, Florida. They travel the following day to their base camp in Sao Paulo.

At the World Cup, they open against Ghana on June 16 at Natal, face Cristiano Ronaldo’s Portugal six days later in the Amazon rain forest city of Manaus and close the group stage against Germany on June 26 at Recife.